— From an engineering point of view, I am essentially a telecom engineer with a specialization in power supplies. Although I do not hold any certificates, I have acquired the necessary knowledge through hands-on experience. — Sometimes I need to dig into the designer's mind to fix a device. That's how I learn things. Telecommunication skills: — Circuit switching: Extensive knowledge base on the architecture of circuit switch, starting from electromechanical switch to digital SPC (Stored Programmed Controlled) switch to all IP soft switch. — Packet switching: Very good knowledge base on packet switching network starting from X.25 (PSPDN) to TCP/IP (de-facto standard) network LAN, MAN, WAN along with packet switch variant like Frame Relay, MPLS, cell switch (ATM). A router is nothing but a layer 3 packet switch. — Signaling protocol: In-depth knowledge base on O&M signaling to channel associated MFC tone to common channel SS7 packet-switched signaling network. These signaling protocols are used in circuit switch to build a wide area to a global telephone network. — Transmission: Extensive knowledgebase on multiplexing of communication channels (analog {FDM} and digital {PCM->PDH, SDH, SONET, ISDN}) to create a baseband for transmission through media like radio (microwave), optical fiber (single lambda, WDM, DWDM), satellite. — Billing: Actively involved in an SW development project for billing of telex switch along with BUET. It was nothing but the crunching of CDR data produced by the telex switch to make a meaningful format of data understandable by a general user. — Power Supplies: Extensive knowledge base on telecom and IT power infrastructure including IPS, single conversion and double conversion UPS, low EMI & low THD rectifiers. — Satellite Communications: In-depth knowledge base on satellite communication systems using FDMA and TDMA. VSAT, thin route DAMA, thick route DAMA are variations in accessing the satellite links. — Mobile communications: Understands the basics of CDMA, GSM RTT for the access network. Computer skills: — I started with DOS 5 as OS and now handling windows 10. I never allowed my PC to crash or show a blue screen. I am an advanced PC user. I did not like windows 8 as it is basically designed for tabs so I stayed with Windows 7. Recently I have upgraded to windows 10. I never went to any person or service provider to fix/repair my PC. — I am very good at handling the MS office suite. I made many macros using office VBA to automate my day-to-day activity in a telephone exchange and other parts of my career. — Besides MS office, I am an advanced user of a 3D CAD application named SOLIDWORKS. I can do stress simulation to validate any design performance and flow simulation to validate HVAC and fluid handling equipment performance before actually building the device. — I am also proficient in handling CorelDraw Suite, Corel paint shop, Wolfram Mathematica, Windows moviemaker, Nero video publishing. Not an expert in these apps but I tend to learn features to integrate across the apps. — Good at computer networking.